Our overall goal is to perform experiments which will provide insight into the synthesis, intracellular transport and secretion of components of the extracellular lining of small airways, and into factors which modulate and influence these processes. We anticipate that these experiments will generate information which will enlarge our understanding of the molecular and cellular basis for conducting airway function. We expect to achieve this objective using combined ultrastructual (morphometry and radioautography) and biochemical techniques in in vivo and in vitro experiments.